allow ptc-encoded entities in fragment

[conitrade-as]

In #305 the fragment matching was improved. However, the current regex does not allow pct-encoded entities (see https://datatracker.ietf.org/doc/html/rfc3986#section-3.5) to be present.

The RFC states that:

• fragment = *( pchar / "/" / "?" )
• pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
• pct-encoded = "%" HEXDIG HEXDIG

The used regular expression does not match the following valid example:

import re
fragment = '2022%201040%20(Cornelius%20Morgan%20G).pdf'
re.fullmatch(r"[0-9a-zA-Z?/:@\-._~!$&'()*+,;=]*", fragment)